Paola Ricciardi

Sound quality indicators for urban places in Paris cross-validated by Milan data

A specific smartphone application was developed to collect perceptive and acoustic data in Paris. About 3400 questionnaires were analyzed, regarding the global sound environment characterization, the perceived loudness of some emergent sources and the presence time ratio of sources that do not emerge from the background. Sound pressure level was recorded each second from the mobile phones microphone during a 10-min period. The aim of this study is to propose indicators of urban sound quality based on linear regressions with perceptive variables. A cross validation of the quality models extracted from Paris data was carried out by conducting the same survey in Milan. The proposed sound quality general model is correlated with the real perceived sound quality (72%). Another model without visual amenity and familiarity is 58% correlated with perceived sound quality. In order to improve the sound quality indicator, a site classification was performed by Kohonens Artificial Neural Network algorithm, and seven specific class models were developed. These specific models attribute more importance on source events and are slightly closer to the individual data than the global model. In general, the Parisian models underestimate the sound quality of Milan environments assessed by Italian people.

Improvement of Façades' Sound Insulation of Schools near the Bergamo - Orio al Serio International Airport: Case Study

In recent years the acoustic qualification of buildings has gained more and more importance at international level. Building renovation is one of the most common ways to improve the acoustic quality of the existing buildings; in particular, schools buildings are the ones that need more attention. In this context, the sound insulation requirements, especially for buildings near airport zones, play a role of primary importance. This paper analyses the data of a campaign of inspections and on-site measurements of façade sound insulation, concerning five public school buildings, close to the international airport of Bergamo - Orio al Serio. The analysis consisted in checking the sound insulation of buildings, after selecting classrooms with common characteristics, based on an accurate preliminary investigation involving more than 395 different characteristics of frames and glass windows. After having determined the D2m,nT,w, the most appropriate technological solutions for a refurbishment project were determined. Finally, the improved façade sound insulation was verified. The refurbishment project took place in 15 classrooms, characterised by a pre-treatment D2m,nT,w lower than 38 dB. Experimental post-treatment results showed that all classrooms satisfied the required basic performance of D2m,nT,w, and 13 of them fulfilled the high performance requirement of 43 dB, established in the Italian acoustic classification.

Climate change and its role in forecasting energy demand in buildings: A case study of Douala City, Cameroon

The foremost role of a building is to assure the comfort of its occupants. The thermal comfort of a building depends on the outdoor climate and requires a demand in energy for heating and cooling. In this paper, demand of energy (heating/cooling) in the buildings is discussed in Douala, Cameroon. Daily data of the last 40 years coming from five weather stations of Cameroon have been studied. Some forecasts have been carried out with 14 GCM models, associated to three future climate scenarios B1, A2, and A1B. However, only INCM3 of General Circulation Model (GCM) and A2 scenario was used. Energy demand in buildings is valued by HDD (heating degree day) and CDD (cooling degree day) indices. Obtained results show that the temperature evolves more quickly in dry season than in rainy season in Douala. Climate rise indicates an increasing demand of energy in the buildings for cooling. Global Douala heating shows a definite effect on outdoor comfort. From 2045 to 2075, the demand of energy for cooling will be superior to 50%. The total demand in energy for heating in the buildings is estimated to be 67.882 kcal from 1970 to 2000 and will be around 67.774 kcal from 2013 to 2043.